What is causing this redirect to non-ssl?

I'm trying to determine what is causing all the pages on a site to redirect to http even when told to go to https. It's on GD shared hosting and is running a Joomla installation on it. No matter what page I visit it is forced to redirect to non-ssl.

I have tried the following:

I have disabled all the redirects in the htaccess file

I verified that the Redirects panel in the cpanel for the account does not have any redirects in there for the pages I am trying to access as https.

I have also turned off the SEF URLs feature in Joomla. (if I tell Joomla to force SSL for all pages the entire site dies with errors saying there are too many redirects).

Even with all of these items turned off every URL you go to on the site still loads as http even though a valid SSL certificate is installed.

Even the 404 errors redirect to http when I just make something up for the address.

If I load the site onto a different server and do the same thing then I can load https with no problem.

What other sources of this redirect might I be missing? The site is marinabaywatch.com. Any ideas would be greatly appreciated.

Re: What is causing this redirect to non-ssl?

Thank you for your post. SSLShopper is showing that the certificate is indeed valid and installed. I found this guide for Joomla that may be helpful as there may be a setting that may need to be modified.